On a turbine blade cascade endwall in a turbine serving as a motive power generator that obtains motive power by converting kinetic energy of a fluid to rotational motion, a so-called “cross flow (secondary flow)” occurs from the pressure side of one turbine blade to the suction side of an adjacent turbine blade.
In order to improve the turbine performance, it is necessary to reduce this cross flow and to reduce secondary-flow loss that occurs due to the cross flow.
Therefore, as a turbine blade cascade endwall that reduces such secondary-flow loss due to a cross flow to improve turbine performance, one having non-axisymmetric irregularities formed thereon has been known (for example, see Patent Document 1).    Patent Document 1: U.S. Pat. No. 6,283,713, Specification.